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Plasmodium Knowlesi


  • The most frequent complication was respiratory distress, which was present at hospital admission in 4 patients and developed after admission in an additional 3 patients.[ncbi.nlm.nih.gov]
  • Malaria may have been a contributory factor rather than the sole cause in our patient who presented with a stroke.[doi.org]
  • CONCLUSIONS: The present study found higher genetic polymorphism in the PkRAP-1 gene than the polymorphism level reported in a previous study.[ncbi.nlm.nih.gov]
  • METHODS: In the present study, we have employed two-dimensional gel electrophoresis-coupled immunoblotting techniques and mass spectrometry to identify novel circulating markers in sera from P. knowlesi-infected patients.[ncbi.nlm.nih.gov]
  • A 23-year old splenectomized patient with beta thalassaemia major presented with fever 11 days after receiving a blood transfusion from a pre-symptomatic donor who presented with knowlesi malaria 12 days following blood donation.[ncbi.nlm.nih.gov]
  • The majority of the vivax patients (65%) were logging-camp workers returning from Asia-Pacific countries with a higher incidence of malaria than the Kapit region.[doi.org]
  • In an initial 2-month pilot study, most cases of P. vivax and P. falciparum infection were among logging camp workers returning from long periods in Oceania or Equatorial Africa, respectively.[doi.org]
  • The distribution may be even more widespread, because human P. knowlesi infections have been found in Thailand [ 10 ] and in China in a logging-camp worker who had recently returned from Myanmar [ 11 ].[doi.org]
  • Splenectomy was performed. Histopathological examination findings were suggestive of splenic rupture and presence of malarial pigment. Analysis of his blood sample by nested PCR assays confirmed P. knowlesi infection.[ncbi.nlm.nih.gov]
  • There are plausible mechanisms for increased haemolysis with hyperparasitaemia, and following both splenectomy and artesunate.[ncbi.nlm.nih.gov]
  • Four days later, he presented to hospital in a state of collapse and died within two hours.[ncbi.nlm.nih.gov]
  • It was due to the presentation of shivering in the ICU, that a blood film was done on the second day that revealed the presence of P. knowlesi with a parasite count of 520,000/μL.[ncbi.nlm.nih.gov]
Chest Discomfort
  • We report a case of severe Plasmodium knowlesi and dengue coinfection in a previously healthy 59-year-old Malay man who presented with worsening shortness of breath, high-grade fever with chills and rigors, dry cough, myalgia, arthralgia, chest discomfort[ncbi.nlm.nih.gov]
Dry Cough
  • We report a case of severe Plasmodium knowlesi and dengue coinfection in a previously healthy 59-year-old Malay man who presented with worsening shortness of breath, high-grade fever with chills and rigors, dry cough, myalgia, arthralgia, chest discomfort[ncbi.nlm.nih.gov]
Productive Cough
  • Fever and chills were present in almost all cases, and other frequent symptoms included abdominal pain, breathlessness, and productive cough. Tachypnea, pyrexia, and tachycardia were common clinical signs ( table 1 ).[doi.org]
  • He also complained of weakness, dyspnea, and cough. He was alert and oriented, but he was dehydrated, jaundiced, and tachypneic. There were bibasal crackles on chest auscultation. Abdominal examination revealed generalized tenderness and guarding.[doi.org]
Severe Clinical Course
  • However, P. knowlesi infection may be associated with rapidly increasing parasitaemia and severe clinical course with the risk of death.[ncbi.nlm.nih.gov]
Abdominal Tenderness
  • He had generalized abdominal tenderness, maximal at the epigastric region. Bedside focused abdominal ultrasonography revealed free fluid in the abdomen.[ncbi.nlm.nih.gov]
  • On examination, he was jaundiced and hypotensive, and he had generalized abdominal tenderness and a palpable spleen. Malaria was suspected, and a blood film was reported to show 112,000 P. malariae parasites/µL.[doi.org]
Epigastric Tenderness
  • She began receiving intravenous rehydration and oral metronidazole, but she became hypotensive overnight and was transferred to the district hospital on day 2, where the main finding of physical examination was epigastric tenderness.[doi.org]
Severe Abdominal Pain
  • All 4 PCR-confirmed fatal cases of P. knowlesi were hyperparasitemic, and all 4 patients presented with severe abdominal pain and a history of fever and chills.[doi.org]
Epigastric Pain
  • A 66-year-old woman presented to her local health post on day 1 with a 3-day history of epigastric pain, diarrhea, vomiting, fever, and rigors. Malaria was not considered to be a possible diagnosis.[doi.org]
  • Hepatosplenomegaly was the only clinical finding; laboratory tests showed thrombocytopaenia, lymphopaenia, mild anaemia and liver transaminitis.[ncbi.nlm.nih.gov]
Retinal Hemorrhage
  • Patients with retinal hemorrhages had lower platelet counts than those without (median, 22 vs 43 10(9)/L; P .04).[ncbi.nlm.nih.gov]
Retinal Pigmentation
  • Nonspecific retinal whitening occurred in 3 (35%) and 5 (29%) patients with severe and nonsevere disease, respectively; hemorrhages in 2 (17%) and 3 (18%); loss of retinal pigment epithelium in 1 (8%) and 4 (24%); and drusen in 9 (71%) and 12 (75%).[ncbi.nlm.nih.gov]
  • Treating the dengue had so distracted the clinicians that a blood film for the malaria parasite was not done.[ncbi.nlm.nih.gov]
  • Symptomatic patients presented mild to moderate symptoms like fever, chills, headache, dizziness, fatigue and myalgia.Although both the intermediate as well as the definite host are known to be endemic in southeastern Bangladesh, no evidence for the presence[ncbi.nlm.nih.gov]
  • Malaria may have been a contributory factor rather than the sole cause in our patient who presented with a stroke.[doi.org]


Rickettsia Typhi
  • Results of dengue reverse transcription–PCR (RT-PCR) on serum, 2 sets of blood cultures, and Rickettsia typhi serologic testing were negative. Results of a chest radiograph and ultrasound of the abdomen were normal.[doi.org]
Liver Biopsy
  • The former becomes mature between the 8th and 9th day after the blood meal, at 26 C. and in a relative humidity of 80 per cent. 6. (6) The pre-erythrocytic schizogony of P. knowlesi is described from forms seen in liver biopsies made, and days after the[doi.org]


  • No randomised controlled trials have been done to identify the optimum treatment for this emerging infection.[ncbi.nlm.nih.gov]
  • Treatment with quinine has been described as a risk factor; however the syndrome may also occur following treatment with intravenous artesunate.[ncbi.nlm.nih.gov]
  • Late treatment failure was seen in one patient with vivax malaria with the presence of a rising parasitaemia on day 4 of treatment.[doi.org]
  • There are no studies assessing the detailed parasitological response to treatment of knowlesi malaria infections in man and whether antimalarial resistance occurs.[ncbi.nlm.nih.gov]
  • KEYWORDS: Plasmodium knowlesi; artemisinin-combination therapy; malaria; treatment[ncbi.nlm.nih.gov]


  • Although late stages of parasites may be visible in the blood in falciparum infections, they are rare and associated with a poor prognosis.[doi.org]
  • Patients with falciparum malaria who develop respiratory distress have a relatively poor prognosis [ 13 ], and both of our patients who died developed this complication.[doi.org]
  • Blood examination and prognosis in acute falciparum malaria . Trans. R. Soc. Trop. Med. Hyg. 43 :33–48 [ PubMed ] [ Google Scholar ] 99. World Health Organization 2011.[ncbi.nlm.nih.gov]


  • Because P. malariae infection was not consistent with the clinical findings of the initial examination, we investigated further to determine the etiology of this case.[doi.org]
  • In our group, a pulmonary, rather than metabolic, etiology was the main cause, because we measured blood lactate concentrations and had access to chest radiographs and pulse oximetry.[doi.org]


  • Epidemiological data on malaria for Sarawak has been derived solely from hospitalized patients, and more accurate epidemiological data on malaria is necessary.[ncbi.nlm.nih.gov]
  • Gov't MeSH terms Amino Acid Sequence Antigens, Protozoan/genetics* Genetic Variation* Humans Malaria/epidemiology Malaria/parasitology Multigene Family Open Reading Frames Phylogeny Plasmodium cynomolgi/classification Plasmodium cynomolgi/genetics* Plasmodium[ncbi.nlm.nih.gov]
  • The molecular, entomological, and epidemiological data indicate that human infections with P. knowlesi are not newly emergent and that knowlesi malaria is primarily a zoonosis.[ncbi.nlm.nih.gov]
  • Although microscopy-identified P. malariae cases have been reported in the state of Sarawak (Malaysian Borneo) as early as 1952, recent epidemiological studies suggest the absence of indigenous P. malariae infections.[ncbi.nlm.nih.gov]
  • High levels of pairwise divergence between each of these sympatric and allopatric subpopulations have implications for the epidemiology and control of this zoonotic species.[ncbi.nlm.nih.gov]
Sex distribution
Age distribution


  • KEYWORDS: Plasmodium knowlesi; in vivo; non-human primate; pathophysiology; severe malaria[ncbi.nlm.nih.gov]
  • However, pathophysiological mechanisms underlying knowlesi malaria, and of the age-related increase in risk of severe malaria in general, are poorly understood.[ncbi.nlm.nih.gov]
  • These results suggest that further study of knowlesi malaria will aid the interpretation of, often conflicting, information on malaria pathophysiology in humans.[ncbi.nlm.nih.gov]
  • The severe form of P. knowlesi malaria can be compared with severe falciparum malaria to inform the pathophysiology of both infections. P. knowlesi presents new challenges to malaria -control efforts in Southeast Asia.[journals.lww.com]


  • The evolution of a rapid diagnostic kit to diagnose P. knowlesi is needed, for early identification and appropriate anti-malarial therapy of suspect cases are both critical in the prevention of the potentially life-threatening disease through P. knowlesi[ncbi.nlm.nih.gov]
  • CONCLUSIONS: Taken together with reports of clinical failures when P. knowlesi is treated with mefloquine, the data suggest that caution is required if using mefloquine in prevention or treatment of P. knowlesi infections, until further studies are undertaken[ncbi.nlm.nih.gov]
  • Intermittent preventive treatment for the prevention of malaria during pregnancy in high transmission areas. Malar J . 2007 Dec 4. 6:160. [Medline] . [Full Text] . Trape JF, Tall A, Diagne N, et al.[medscape.com]
  • Additional management strategies are therefore needed to prevent and reduce severity of AKI in malaria.[hotnorth.org.au]
  • There are many gaps in our understanding of this disease that are highlighted here with suggestions for further research to inform pre-emptive control measures that would be required to prevent a full emergence of this parasite into the human population[ncbi.nlm.nih.gov]

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